Mauricio Pochettino felt Saints lost at Upton Park because West Ham had the “effectiveness” they lacked.
The Saints boss, who reversed the six changes he had made for the FA Cup defeat at Sunderland the previous weekend, saw his side’s six-game Premier League unbeaten run come to an end.
Saints dominated much of the game, boasting 69 per cent possession and having 25 shots, yet they ended up on the wrong end of a 3-1 scoreline.
Pochettino said: “I do like statistics to justify the defeat.
“I am very disappointed with the defeat. I felt we fully deserved to get something more from the game.
“We had full control of the game and that led us to get the 1-0.
“It’s clear that the 1-1 came from an offside position and that was unlucky for us and the team struggled to recover from the 2-1 which made everything difficult for us.
“I thought in the second half we created many good chances and we were unlucky not to get the 2-2 that would have changed the game.
“I thought overall we were quite unlucky with the refereeing decisions and that we didn’t score more goals.”
Saints were frustrated that West Ham’s first goal, an equaliser to Maya Yoshida’s early header, wasn’t ruled out for offside.
But the boss didn’t accept too much criticism of his players defensively for the other two Hammers goals.
“I thought we were unlucky for the first goal so we can leave that goal aside because it shouldn’t have gone to 1-1,” he reflected.
“In their second goal three of our players were unable to clear the ball. It was just one of those moments where there was indecision in the box.
“Then we were looking for the equaliser, the 2-2, they came strong on the counter attack and we know of Cole and Nolan’s strengths, they are very strong players.
“I thought the team worked very well.
“We knew it was going to be a very tough game against very good opposition and we lacked exactly what they had – effectiveness.”